Indicator



Patented Nov. 6, 1945 INDICATOR Edward V. Sundt. Arcadia, and Joseph Purcell, El'Monte, Calif., assignors to Littelfuse, Inc., Chicago, 111., a corporation of Illinois Application May 3, 1943, Serial No. 485,476

6- Claims. (01. 177-329) This invention relates to improvements in indi- I cators.

One object of the invention is to provide a readily visible indicator adapted for use under various conditions of lighting, as for example in the cock pit of a military plane where the interior at times may be illuminated by bright sunlight and at other times, as during black-outs, may be completely devoid of artificial illumination or subjected only to the so-called black light from a source of ultra-violet radiations. The employment of incandescent tell-tale lamps as indicators frequently is not satisfactory, especially in military planes, since in bright day-light the lamps frequently are not readily visible and m black-outs they sometimes disturb the ocular adjustment of the pilots notwithstanding the lamps may emit light of low intensity.

An additional object of the invention is to pro- I vide an indicator for indicating the proper functioning of an instrument or. like device which preferably provides a relatively large luminous area of low intensity-light reflection or radiation which is easily visible in daylight or in darkness.

In carrying out the objects of the invention, use is. made of the known properties of luminous substances which glow or are phosphorescent in The illustrated indicator is provided with a tubular iron casing l0 threaded on its exterior as indicated at H and carrying a pair of nuts l2,

l3 and an interposed lock washer l4 for clamping the indicator in position in an opening in a panel, instrument board or dash IS. The nut 13 abuts a shoulder l6 formed by an enlarged end of the casing, as shown in Fig. 2. A bezel I1 is shown on the enlarged end, which may be threaded thereto for retaining a suitable domeshap ed lens or crystal l8.over the end of the indicator. Within the inclosure provided by the dome-shaped lens l8 and the adjacent end of the casing III is a pair. of pivotally connected. vanes I9. The vanes are shown mounted on a pintle 20 the ends of which are supported in receiving apertures 2| provided in the casing Ill. The vanes .are semi-circular in shape and are movable from the parallel position shown in full lines'to the open position shown in dotted lines in Figs 2. The movement of the vanes simulates movement of butterfly wings. The outer faces of vanes l9, that is, the faces that are in juxtaposition when the vanes are parallel, preferably are coated with a radio-active or luminescent substance, preferably in the form of luminous paint 22 having suitable light emitting characteristics such that in the dark the surfaces glow or are phosphorescent and will become fluorescent when subjected to ultra-violet or dark light as from a source thereof within an airplane cockpit. The pigment of the paint employed preferably is such also that it is easily visible in daylight by contrast with the surrounding adjacent usually blacksurfaces. Preferably the color of the light which is reflected or emanates from the wing surface under the various light conditions mentioned, is uniform, or substantially so.

For the purpose of moving the vanes I9 in unison from the closed or non-indicating positions to the open or indicating positions suitable means are provided which respond to a condition or change in condition to be indicated. For example, thermostatic means may be employed for operating the vanes but in theillustrated embodiment of the invention electro-magnetic means are provided which can conveniently be connected in series or parallel with a circuit of an instrument or device if electrically operated, or be controlled by means of a relay or otherwise for indicatingwhether. the instrument or device is or is not in operation. The vane operating mechanism comprises a stationary solenoid core 23 surrounding which is a non-magnetic seamless cylindrical sleeve 24 of conducting material, as brass, on which is a D. C. solenoid winding 25. The ends of the winding pass through apertures in an insulating end plug 26 secured to the core 23' by a screw 21 and electrically connected to terminals 28 carried by the plug.

The forward end of the core 23 is provided with centering means in the form of a non-ferrous pin 29 for guiding a reciprocal armature. which has a central aperture into which the pin extends.

The inner end of the armature is slightly smaller in diameter than the tube 24 and is slidable within the adjacent end of the tube while anenlarged outer end 30a of the armature. moves within the outer end portion of the casing Ill. Thepin 29 armature for actuation thereby to and from the 7 open and closed positions. The connecting means" shown comprise links 32 pivotally secured to the rear faces of the vanes bywire eyes 33- and to the armature by eyes 34. By reason ofthe construction shown, the armature draws the .Vanes to the open position (shown in dotted lines in Fig.

3) when the winding is energized, and retains the vanes in the open position until the circuit of the solenoid is opened whereupon the spring 3| movesthe armature outwardly which effects closing or folding of the vanes into theparallel relation shownin full lines in Fig. 2. When the vanes are in the closedor parallel :relation they are disposed substantially diametrically of thef device and in said positions the luminescent material on the vanes is concealed and hencemay indicate that the instrument or device is not in operation, for example. While the coil is energized, the vanes are in the open position thus exposing the fluorescent or luminescent surfaces and giving an indication of the operation ofthe associated instrument or device.

The vanes preferably are semi-circular as shown and as will be seen when open extend substantially transversely of the device and present a light reflecting or emitting area not substantially less than the cross sectional area of the .casing ID. The arrangement thus provides relatively large light reflecting or emitting surfaces in proportion to the area of the mounting panel occupied by the, portion. of the device that is visible from the forward side of the mountin panel.

It will be noted in Fig. 2 that the link mechanism therein illustrated is such that the armature does not open the vanes a full 180. In fact in the open position the vanes preferably form an angle of about140 since at the latter angle the visibility of the vanes by a pilot appears to be improved. The extent of the vane opening movement can be varied as may be desirable by altering the link mechanism depending on positions of location of the indicator with respect to ,the line of vision of the pilot.

As will be seen the flow of current through the coil energizes the solenoid and draws the armature 30 inwardly along the guiding pin 29, thereby swinging the indicator vanes to open position. Opening the circuit of the indicator enables the spring 31 to return the vanes to closed or folded parallel relation, wherein the treated surfaces are mutually concealed by the vanes. The conductive, non-ferrous sleeve 24 acts as a short-circuiting turn for the coil 25 and reacts against the voltage surge induced in the coil .upon opening the circuit and. thereby reduces the inductive surge which might otherwise damage the insulation of the magnet winding.

While one illustrative embodiment of the invention has been shown and described it will be apparent that various changes inv the details of construction thereof may be made without departing from the spirit of the invehtionar .7 l I weclaimz said parallel 1. An indicator comprising a pair or pivotally mounted vanes swingable from an angular relation into close parallel relation and vice versa, luminescent material on the forward contiguous surfaces of the vanes whereby the material of both vanes is concealed mutually by the vanes when the latter are in said parallel relation, and

means operatively connected to opposite portions of the vanes for moving the latter in unison from either of said positions to the other.

2. An indicator cOmpriSing an armature, means 'for operating the same comprising electro-magnetic means for operating the same in one direction and a spring biasing the armature for operation in theopposi'te direction, a pair of adjacently pivotally ,mounted indicating members thereof whereby the members mutually conceal the material when in said close parallel relation 'and effect exposure of the material when in the angular indicating relation, and means operatively connecting said members to said armature for pivotal operation by the latter from one of said positions to the other when the armature is operated by said armature operating means.

3. An indicator comprising a casing adapted to be mounted in an opening in a panel, said casing having a lens'opening therein, a convex lens over said lens opening on the exposed end of the casing, a pair of semi-circular vanes beneath the lensmountedon a common pintle for swinging movement from parallel contacting positions to open angular positions; luminescent material on the contiguous faces of said vanes exposed when the latter are in said open angular positions and concealedby the vanes when in positions, an electro-magnetic means in said casing comprising a reciprocable armature operatively connected to said vanes for moving the same from one of said positions to .the other.

4. An indicator comprising a cylindrical casing adapted to be positioned in anaperture of a panel with one end thereof exposed, saidcasing having a lens opening in .said exposed end, a pair of semi-circular vanes pivotally vmounted within said end of the casing on a common pintle extending diametrically of said casing and having radii such that the combined area of the outer faces of the vanes is substantially equal to the cross sectional area of the casing, a domeshaped lens mounted on saidend of the casing over said lens opening and beneath which'said 'concealed by the vanes when in parallel relation,v and electro-magnetic means in said casing for operating the vanes from one of said positions to the other.

5. An indicator comprising a casing provided with an opening and adapted to'be mountedin an opening in a panel, a pair of swingable vanes in the forward end of the casing each pivotally 'mounted' for opposite'movement from closely spaced parallel. positions to open' angular posi- 'tions and viceversa and being visible through said opening. :in: said casing, indicating material on the contiguous faces of said vanes exposed when the latter are in said open angular positions and concealed by the vanes when the latter are in said parallel positions, and means in said casing comprising a. reciprocable armature operatively connected to said vanes for moving the same from one of said positions to the other.

6. An indicator comprising a cooperating pair of vanes each provided with indicating material on the forward surface thereof, means pivotally mounting the vanes at correspondin edges thereof whereby the vanes are movable from contacting parallel positions wherein each vane conceals the indicating material of the other vane to angular positions wherein the material of said surfaces is exposed, a spring biased reciprocable member positioned rearwardly of said vanes and operatively linked thereto for moving the vanes to one of said positions from the other, and electromagnetic means for actuating said reciprocable member in a direction against the biasing action of the spring for operating each of the vanes from the spring biased position to said other position.

EDW. V. SUNDT.

JOSEPH PURCELL. 

